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1.
Zhonghua Nei Ke Za Zhi ; 59(2): 161-164, 2020 Feb 01.
Artigo em Chinês | MEDLINE | ID: mdl-32074693

RESUMO

A 49-year-old woman was admitted to hospital with intermittent dizziness and fatigue for 7 years. The symptoms were aggravated and accompanied by bone pain for more than 4 months. She was referred to our hospital. Laboratory tests and imaging findings suggested that acquired Fanconi Syndrome (FS) was associated with smoldering multiple myeloma (MM). Renal biopsy and electron microscopy confirmed the diagnosis of proximal light chain tubular disease (LCPT). LCPT causes proximal tubular dysfunction, which is characterized by the cytoplasmic crystal deposition usually kappa monoclonal light chain in the proximal tubule. MM with FS and LCPT is less common in clinical practice because it is difficult to diagnose. This is a typical case focusing on the differential diagnosis of monoclonal gammopathy of renal significance(MGRS) such as LCPT and plasma cells diseases.


Assuntos
Anemia , Tontura/etiologia , Síndrome de Fanconi/etiologia , Fadiga/etiologia , Nefropatias/complicações , Mieloma Múltiplo , Paraproteinemias/complicações , Proteinúria , Síndrome de Fanconi/diagnóstico , Feminino , Humanos , Cadeias kappa de Imunoglobulina , Nefropatias/diagnóstico , Pessoa de Meia-Idade , Paraproteinemias/diagnóstico
2.
Klin Monbl Augenheilkd ; 237(1): 41-45, 2020 Jan.
Artigo em Alemão | MEDLINE | ID: mdl-31968365

RESUMO

Necrobiotic xanthogranuloma is a very rare disease with granulomatous lesions of the skin with possible association with paraproteinemia. We report two cases of orbital necrobiotic xanthogranuloma in patients with mono/biclonal gammopathy of undetermined significance. Both patients underwent successful conservative treatment.


Assuntos
Xantogranuloma Necrobiótico , Paraproteinemias , Humanos , Xantogranuloma Necrobiótico/complicações , Xantogranuloma Necrobiótico/diagnóstico , Paraproteinemias/complicações , Paraproteinemias/diagnóstico
4.
Ann Lab Med ; 40(3): 193-200, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31858758

RESUMO

BACKGROUND: Waldenström macroglobulinemia (WM) is a subset of lymphoplasmacytic lymphoma (LPL) with bone marrow (BM) involvement and an IgM monoclonal gammopathy of any level. We aimed to identify the clinical, laboratory, and BM findings of patients with WM and to evaluate the usefulness of CD154 for the diagnosis and prognosis of WM. METHODS: We reviewed the medical records and BM studies and/or flow cytometric immunotyping of 31 patients with untreated WM. Semiquantitative immunohistochemistry (CD20, CD138, tryptase, and CD154) of BM was performed. RESULTS: Only six patients presented with symptoms of hyperviscosity syndrome. Eleven patients had solid cancer and/or another hematologic malignancy. Mast cells (MC) increased in all samples, with some in close contact with tumor cells. Tryptase-positive MC (17.1/ high-power fields [HPF], 1.2-72.0/HPF) and CD154-positive MC (8.6/HPF, 0.1-31.1/HPF) were observed. The high CD154-positive MC (≥8.6/HPF) group showed a lower overall five-year survival rate than the low CD154-positive MC (<8.6/HPF) group (71.9% vs. 100.0%; P=0.012). Flow cytometric immunophenotyping of BM aspirates showed increased B lymphocytes and plasma cells with a normal phenotype (CD138⁺/CD38⁺/CD19⁺/CD45⁺/CD56⁻). CONCLUSIONS: Approximately one third of WM patients showed other malignancies and all patients had increased MC. Immunohistochemistry and flow cytometric immunophenotyping are useful for diagnosing WM, and increased CD154-positive MC can indicate poor prognosis.


Assuntos
Medula Óssea/patologia , Macroglobulinemia de Waldenstrom/diagnóstico , Idoso , Idoso de 80 Anos ou mais , Antígenos CD20/metabolismo , Linfócitos B/citologia , Linfócitos B/metabolismo , Medula Óssea/metabolismo , Ligante de CD40/metabolismo , Diagnóstico Diferencial , Citometria de Fluxo/métodos , Humanos , Imunofenotipagem , Estimativa de Kaplan-Meier , Mastócitos/citologia , Mastócitos/metabolismo , Pessoa de Meia-Idade , Paraproteinemias/complicações , Paraproteinemias/diagnóstico , Plasmócitos/citologia , Plasmócitos/metabolismo , Estudos Retrospectivos , Macroglobulinemia de Waldenstrom/complicações , Macroglobulinemia de Waldenstrom/mortalidade
5.
Biochem Med (Zagreb) ; 30(1): 010801, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31839726

RESUMO

This is a case report of a challenging diagnosis of IgE monoclonal gammopathy of undetermined significance, which transformed into myeloma, then transformed into IgE-producing plasma cell leukaemia in a 71-year-old male who was followed in Brest, France, from 2015 to 2019. The IgE-producing variant is the rarest sub-type of multiple myeloma, and plasma cell leukaemia is considered to be the rarest and the most aggressive of human monoclonal gammopathies. In November 2015, hypogammaglobulinemia was detected during a systematic check-up. A kappa light chain monoclonal gammopathy was first diagnosed due to an increase of the free kappa/lambda light chains ratio. No monoclonal immunoglobulin was detected by either serum protein electrophoresis (Capillarys 2, Sebia, Issy-les-Moulineaux, France) or immunofixation (Hydrasys 2, Sebia, Issy-les-Moulineaux, France). In June 2018, a blood smear led to the diagnosis of plasma cell leukaemia. A monoclonal peak was detected and identified as IgE-kappa. Analysis of an archival sample taken three years earlier, revealed the presence of a monoclonal IgE, which had been missed at diagnosis. Chemotherapy with bortezomib and dexamethasone was introduced. The patient survived 10 months after the diagnosis of leukaemia. This case shows that an abnormal free light chain ratio should be considered as a possible marker of IgE monoclonal gammopathy even in the absence of a solitary light chain revealed by immunofixation. In addition, the use of an undiluted serum may increase the sensitivity of the immunofixation for the detection of IgE monoclonal gammopathies compared to the 1:3 dilution recommended by the manufacturer.


Assuntos
Imunoglobulina E/metabolismo , Leucemia Plasmocitária/diagnóstico , Idoso , Antineoplásicos/uso terapêutico , Bortezomib/uso terapêutico , Dexametasona/uso terapêutico , Humanos , Leucemia Plasmocitária/tratamento farmacológico , Masculino , Paraproteinemias/diagnóstico , Plasmócitos/patologia
6.
Rev Med Chil ; 147(8): 1036-1041, 2019 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-31859969

RESUMO

Hematological neoplasms are tumors of cells in different states of maturation and differentiation. Since monoclonal gammopathies (MG) refer to B mature lymphocyte neoplasms, lymphogenesis should be well known. We must keep in mind that the last stage of maturation of these lymphocytes is the plasma cell. This is how a MG could appear in the context of a plasma cell neoplasm, such as multiple myeloma or amyloidosis, but also in relation to a lymphoma. A monoclonal peak is produced by mature B lymphocytes or plasma cells that secrete a monoclonal protein (Immunoglobulin), and represents a MG. But it must be emphasized that, in the correct clinical context, a hypogammaglobulinemia can represent a MG as well. Another important point is the understanding and interpretation of requested tests, such as protein electrophoresis (PEP), immunofixation (IFx) or serum free light chains (sFLC). The current MG screening panel includes these three studies (PEF, IFx, sFLC), although a simpler panel measuring PEF and sFLC has also been proposed, but not yet formally validated. Therefore, screening done only with PEP is insufficient.


Assuntos
Neoplasias de Plasmócitos/sangue , Paraproteinemias/sangue , Paraproteínas/análise , Linfócitos B/metabolismo , Eletroforese das Proteínas Sanguíneas/métodos , Humanos , Neoplasias de Plasmócitos/diagnóstico , Paraproteinemias/diagnóstico
8.
Cardiol Clin ; 37(4): 487-495, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31587789

RESUMO

Light chain amyloidosis is a deadly disease in which a monoclonal plasma cell dyscrasia produces misfolded immunoglobulin light chains (AL) that aggregate and form rigid amyloid fibrils. The amyloid deposits infiltrate one or more organs, leading to injury and severe dysfunction. The degree of cardiac involvement is a major driver of morbidity and mortality. Early diagnosis and treatment are crucial to prevent irreversible end-organ damage and improve overall survival. Treatment of AL cardiac amyloidosis involves eliminating the underlying plasma cell dyscrasia with chemotherapy and pursuing supportive heart failure management.


Assuntos
Amiloidose , Cardiomiopatias , Gerenciamento Clínico , Diagnóstico Precoce , Paraproteinemias/complicações , Amiloidose/diagnóstico , Amiloidose/etiologia , Amiloidose/terapia , Cardiomiopatias/diagnóstico , Cardiomiopatias/etiologia , Cardiomiopatias/terapia , Humanos , Paraproteinemias/diagnóstico
10.
Ann Clin Lab Sci ; 49(4): 439-447, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31471332

RESUMO

Monoclonal gammopathy of renal significance (MGRS) is a state of circulating monoclonal immunoglobulin (Ig) and light chains that cause kidney injury without definite evidence of multiple myeloma (MM). Although chemotherapy is used to treat many variants of MGRS and has been recently recommended, relatively limited clinical validation studies are available. A few transgenic models of MM reveal renal deposition of monoclonal Ig and light chains. We have demonstrated that the XBP1s-transgenic mouse model from early plasma cell dyscrasia to MM reveals monoclonal IgG/kappa deposition at the subendothelial spaces of the glomeruli, mimicking proliferative glomerulonephritis with monoclonal immunoglobulin deposits. Inhibition of a key immune-modulator, gp96/grp94, genetically or pharmacologically results in a significant reduction of plasma cells within the bone marrow and reduced renal deposition of monoclonal IgG and kappa light chain. This article will review the emerging role of in vitro and animal models from plasma cell dyscrasia to MM in understanding the renal deposition of monoclonal Ig and light chains, along with its potential treatment strategies.


Assuntos
Modelos Animais de Doenças , Paraproteinemias/patologia , Animais , Creatinina/sangue , Humanos , Cadeias Leves de Imunoglobulina/metabolismo , Túbulos Renais/lesões , Túbulos Renais/patologia , Paraproteinemias/classificação , Paraproteinemias/diagnóstico , Paraproteinemias/terapia
11.
Ann Biol Clin (Paris) ; 77(4): 397-406, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31418701

RESUMO

Immunoglobulin light chains are called free when they are not linked with heavy chains to form a whole immunoglobulin. Quantification of free light chains is a part of the French national authority for health guidelines for diagnostic and follow-up of light chain, oligo or non-secretory myeloma and AL amyloidosis. Most recently, the World health organisation had included free light chains quantification in prognostic criteria for monoclonal gammopathy of undetermined significance. However the literature bring to light some other potential indications of this analysis in the exploration of monoclonal gammopathy, also in lymphoid malignancies and some autoimmune diseases such as diabetes, rheumatoid arthritis, systemic lupus erythematosus, multiple sclerosis and Sjögren syndrome.


Assuntos
Doenças Autoimunes/diagnóstico , Neoplasias Hematológicas/diagnóstico , Cadeias Leves de Imunoglobulina/sangue , Paraproteinemias/diagnóstico , Testes Sorológicos , Doenças Autoimunes/sangue , Doenças Autoimunes/imunologia , Diagnóstico Diferencial , Neoplasias Hematológicas/sangue , Neoplasias Hematológicas/imunologia , Humanos , Cadeias Leves de Imunoglobulina/análise , Amiloidose de Cadeia Leve de Imunoglobulina/sangue , Amiloidose de Cadeia Leve de Imunoglobulina/diagnóstico , Gamopatia Monoclonal de Significância Indeterminada/sangue , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico , Paraproteinemias/sangue , Paraproteinemias/imunologia , Valor Preditivo dos Testes , Prognóstico , Testes Sorológicos/métodos , Testes Sorológicos/normas
12.
Pan Afr Med J ; 32: 161, 2019.
Artigo em Francês | MEDLINE | ID: mdl-31303930

RESUMO

Serum protein electrophoresis (SPE) is a routine analysis in the daily practice of a medical biology laboratory. This study aimed to analyze the different electrophoretic profiles seen in our current practice. We conducted a cross-sectional study of 410 serum samples collected during the routine analyses in the Laboratory of Biochemistry at the University Hospital Mohammed VI in Oujda. Serum protein electrophoresis was performed using automated instrument CAPILLARYS 2 FLEX-PIERCING, SEBIA. 241 sera from women and 169 sera from men were collected. Patients were aged between 1-91 years, with an average age of 49 years; 19.5% of SPEs were normal, hypoalbuminemia was found in 34% of cases, chronic inflammatory syndrome in 19.5% of cases, nephrotic syndrome in 2% of cases, 5.8% of our patients had betagamma block, hypogammaglobulinemia was found in 8.5% of cases and 29 monoclonal peaks were noted, bisalbuminemia was found in 2 patients. Out of 410 collections: 92 immunofixations were performed, of whom 23 were positive (showing monoclonal gammopathy). This study highlights the variability in prescribing serum protein electrophoresis as well as the importance of clinical data for a better interpretation.


Assuntos
Eletroforese das Proteínas Sanguíneas/métodos , Hipoalbuminemia/diagnóstico , Inflamação/diagnóstico , Paraproteinemias/diagnóstico , Adolescente , Adulto , Agamaglobulinemia/diagnóstico , Agamaglobulinemia/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Hospitais Universitários , Humanos , Hipoalbuminemia/epidemiologia , Lactente , Inflamação/epidemiologia , Masculino , Pessoa de Meia-Idade , Síndrome Nefrótica/diagnóstico , Síndrome Nefrótica/epidemiologia , Paraproteinemias/epidemiologia , Adulto Jovem
14.
Ann Lab Med ; 39(6): 561-565, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31240884

RESUMO

POEMS syndrome is a rare paraneoplastic syndrome, which includes polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes due to plasma cell (PC) neoplasm. Diagnosis of this disease is challenging because of its rarity and complex clinical manifestations. We attempted to identify the key clinical features and characteristic bone marrow (BM) findings of POEMS syndrome, by reviewing the medical records and BM analyses of 24 Korean patients. Frequent clinical manifestations included polyneuropathy (100%), monoclonal gammopathy (100%), organomegaly (92%), extravascular volume overload (79%), and endocrinopathy (63%). The BM analyses revealed mild PC hyperplasia (median PCs: 5.5%) and frequent megakaryocytic hyperplasia (88%), megakaryocyte clusters (88%), and hyperlobation (100%). Flow cytometry of BM aspirates using CD138/CD38/CD45/CD19/CD56 showed normal (67%, 4/6) or neoplastic PC immunophenotypes (33%, 2/6). A diagnosis of POEMS syndrome must be considered when a patient suspected of having PC dyscrasia shows the above clinical presentation and BM findings.


Assuntos
Medula Óssea/metabolismo , Síndrome POEMS/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD19/metabolismo , Medula Óssea/patologia , Feminino , Glicoproteínas/análise , Humanos , Imunofenotipagem , Linfócitos/citologia , Linfócitos/metabolismo , Masculino , Pessoa de Meia-Idade , Paraproteinemias/diagnóstico , República da Coreia , Estudos Retrospectivos , Adulto Jovem
15.
Rev. lab. clín ; 12(2): 98-101, abr.-jun. 2019. ilus, tab, graf
Artigo em Espanhol | IBECS | ID: ibc-187058

RESUMO

El fósforo es el segundo mineral más abundante en el organismo. Su homeostasis se consigue mantener a través de varios mecanismos mediados principalmente por el riñón, el intestino y el hueso. Se han descrito interferencias en la medición del fósforo que pueden provocar una seudohiperfosfatemia. La causa más frecuente es la presencia de una paraproteína en el suero de los pacientes con mieloma múltiple, macroglobulinemia de Waldenström y gammapatía monoclonal de significado incierto. En los casos de hiperfosfatemia sin causa aparente que la pueda justificar, es importante tener en cuenta la existencia de una seudohiperfosfatemia causada por la presencia de las paraproteínas en sangre en los autoanalizadores de química líquida. El sistema multicapa de Vitros(R) 5600 es un método rápido y fiable para solucionar este problema


Phosphorus is the second most important mineral in the body. Its homeostasis is maintained through several mechanisms mediated mainly by the kidney, intestine, and bone. Interferences have been described in the measurement of phosphorus that could suggest a pseudo-hyperphosphataemia. The most frequent cause was the presence of a paraprotein in the serum of patients with multiple myeloma, Waldenström macroglobulinaemia, or monoclonal gammopathy of uncertain significance, was described as the most frequent cause of interference in phosphorus assay using liquid chemistry autoanalysers. When hyperphosphataemia is present, and no apparent cause can justify it, it is important to consider the possibility of a pseudo-hyperphosphataemia caused mainly by the presence of a paraprotein. The Vitros(R) 5600 multilayer system can be used as a fast and reliable method to avoid this interference


Assuntos
Humanos , Masculino , Idoso de 80 Anos ou mais , Hiperfosfatemia/diagnóstico , Transtornos das Proteínas Sanguíneas/diagnóstico , Mieloma Múltiplo/sangue , Fósforo/sangue , Paraproteinemias/diagnóstico , Biomarcadores/análise , Análise Química do Sangue/instrumentação
16.
Blood Cancer J ; 9(6): 49, 2019 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-31101803

RESUMO

Monoclonal gammopathies (MG) constitute a spectrum of disorders starting from a monoclonal gammopathy of undetermined significance (MGUS) to active disease requiring therapy such as multiple myeloma. MG are characterized by proliferation of clonal plasma cells (PC) secreting a monoclonal protein either as intact immunoglobulin or free kappa or lambda free light chains (FLC). We hypothesized that a polyclonal elevation of serum FLC may indicate an inflammatory state that precedes development of MG. We studied 15,630 individuals from Olmsted county, who did not have MGUS based on baseline screening studies. At a median follow-up of 18.1 years, 264 patients had developed a clonal PC disorder; 252 with MGUS, 1 with SMM, 8 with MM, and 3 with amyloidosis, translating to an annual incidence of development of a MG of 0.1%. We examined the baseline polyclonal ΣFLC (kappa + lambda FLC) from the initial screening and grouped them into deciles. The highest decile group had a 2.6-fold (95% CI; 1.8, 3.7) increase in the risk of developing a MG, P < 0.001. We demonstrate for the first time, the increased risk of developing MG in patients with elevated serum FLC, suggesting that an underlying inflammatory state may play an etiologic role.


Assuntos
Evolução Clonal/genética , Cadeias Leves de Imunoglobulina/genética , Paraproteinemias/epidemiologia , Paraproteinemias/etiologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Suscetibilidade a Doenças , Feminino , Humanos , Cadeias Leves de Imunoglobulina/sangue , Masculino , Pessoa de Meia-Idade , Gamopatia Monoclonal de Significância Indeterminada/diagnóstico , Gamopatia Monoclonal de Significância Indeterminada/epidemiologia , Gamopatia Monoclonal de Significância Indeterminada/etiologia , Proteínas do Mieloma , Paraproteinemias/sangue , Paraproteinemias/diagnóstico , Vigilância da População , Medição de Risco , Fatores de Risco
17.
Acta Ophthalmol ; 97(7): e987-e992, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31044553

RESUMO

PURPOSE: To describe the ocular findings of 12 subjects with paraproteinemic keratopathy associated with monoclonal gammopathy of undetermined significance (MGUS). METHODS: Ocular examination included corneal spectral domain optical coherence tomography. In three individuals with an initial diagnosis of a lattice or Thiel-Behnke corneal dystrophy, the TGFBI gene was screened by conventional Sanger sequencing. RESULTS: We confirmed a diagnosis of MGUS by systemic examination and serum protein electrophoresis in 12 individuals (9 males and 3 females), with a mean age at presentation of 52.2 years (range 24-63 years) and mean follow-up 6.4 years (range 0-17 years). The best-corrected visual acuity (BCVA) at presentation ranged from 1.25 to 0.32. In all individuals, the corneal opacities were bilateral. The appearances were diverse and included superficial reticular opacities and nummular lesions, diffuse posterior stromal opacity, stromal lattice lines, superficial and stromal crystalline deposits, superficial haze and a superficial ring of hypertrophic tissue. In one individual, with opacities first recorded at 24 years of age, we documented the progression of corneal disease over the subsequent 17 years. In another individual, despite systemic treatment for MGUS, recurrence of deposits was noted following bilateral penetrating keratoplasties. The three individuals initially diagnosed with inherited corneal dystrophy were negative for TGFBI mutations by direct sequencing. CONCLUSION: A diagnosis of MGUS should be considered in patients with bilateral corneal opacities. The appearance can mimic corneal dystrophies or cystinosis. In our experience, systemic treatment of MGUS did not prevent recurrence of paraproteinemic keratopathy following keratoplasty.


Assuntos
Córnea/patologia , Opacidade da Córnea/etiologia , Previsões , Ceratoplastia Penetrante/efeitos adversos , Gamopatia Monoclonal de Significância Indeterminada/complicações , Paraproteinemias/complicações , Adulto , Idoso , Opacidade da Córnea/diagnóstico , Feminino , Seguimentos , Humanos , Masculino , Microscopia Confocal , Pessoa de Meia-Idade , Paraproteinemias/diagnóstico , Recidiva , Microscopia com Lâmpada de Fenda , Tomografia de Coerência Óptica , Acuidade Visual , Adulto Jovem
18.
Clin Lab ; 65(5)2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-31115238

RESUMO

BACKGROUND: Determination and quantification of serum free light chains (FLC) is essential for the diagnosis and monitoring of patients with monoclonal gammopathies. Currently, the Freelite assay (The Binding Site, United Kingdom) and the N Latex FLC assay (Siemens Healthineers, Germany) are available for FLC determination. Data concerning stability of FLC following long-term storage are limited. Therefore, the aim of the present study is to investigate the stability of FLC in frozen samples determined by the N latex FLC assay. METHODS: One hundred eighty-eight serum samples from 47 patients with monoclonal gammopathies were analyzed at the beginning and after long-term storage (-20°C, 193 - 568 days). Serum free light chain kappa (κFLC) and lambda (λFLC) concentrations were measured, and the corresponding kappa/lambda (κ/λ FLC) ratios were calculated. All samples were analyzed with the N latex FLC assay on a single BNII System. RESULTS: Comparison analyses between fresh and stored samples revealed very strong correlations for the determination of κFLC (r = 0.993), λFLC (r = 0.998) and the calculated κ/λ FLC ratio (r = 0.997). Median percentage changes of κFLC (-0.5%) and λFLC (-0.8%) measurements and the calculated κ/λ FLC ratios (-3.7%) were within the calculated analytical imprecision of the FLC assay. Changes of κFLC (r = 0.17, p = 0.02) and λFLC (r = 0.28, p < 0.01) concentrations and of the κ/λ FLC ratio (r = 0.18, p = 0.01) over time were very weak, but statistically significant. CONCLUSIONS: Serum free light chains in serum samples are sufficiently stable following long-term frozen storage and are therefore suitable to be measured with the N Latex FLC assay.


Assuntos
Preservação de Sangue/métodos , Criopreservação/métodos , Cadeias Leves de Imunoglobulina/sangue , Cadeias kappa de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/sangue , Paraproteinemias/sangue , Humanos , Cadeias Leves de Imunoglobulina/química , Cadeias kappa de Imunoglobulina/química , Cadeias lambda de Imunoglobulina/química , Látex/química , Paraproteinemias/diagnóstico , Estabilidade Proteica , Reprodutibilidade dos Testes , Fatores de Tempo
20.
Lab Med ; 50(4): 381-389, 2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-30957173

RESUMO

BACKGROUND: Serum free light chain assay is used in the diagnosis and monitoring of monoclonal gammopathic manifestations. For the kappa (κ)/lambda (λ) ratio, there is a 36% false-positive rate in patients without monoclonal gammopathic manifestations and a 30% false-negative rate in patients with monoclonal gammopathic manifestations. This study was undertaken to address the higher false-negative rate in λ chain-associated monoclonal lesions. METHODS: Results of serum protein electrophoresis, serum immunofixation electrophoresis, and serum free light chain assays were reviewed retrospectively. The results for serum free light chains in cases of intact immunoglobulin monoclonal gammopathic manifestations only were analyzed. RESULTS: Concentrations of involved serum free light chains were significantly higher in κ chain-associated lesions than in λ chain-associated lesions. The concentration of uninvolved light chains was significantly higher in λ chain-associated lesions. CONCLUSIONS: κ light chains are present in significantly greater abundance than are λ chains in their respective monoclonal lesions. Moreover, κ and λ light-chain levels are not comparable for similar quantitative levels of monoclonal immunoglobulins. The findings warrant a reconsideration of the role of serum free light chain concentrations and involved to uninvolved serum free light chain ratio in designation of myeloma-defining conditions and other diagnostic criteria based on serum free light chain assay.


Assuntos
Testes Diagnósticos de Rotina/métodos , Cadeias Leves de Imunoglobulina/sangue , Paraproteinemias/diagnóstico , Erros de Diagnóstico , Humanos , Estudos Retrospectivos
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